Hot air furnace



May 12, 1931. I f- 1,804,851 HOT AIR FURNACE I Filed Sept. 12, 1927INVENTOR.

,Jaqz; E -mmfwm A TTORNE Y.

Patented May 12, 1931 v v UNITED STATES JAMES ELIPI-IAS WITTE, 0FNEWPORT, KENTUCKY nor AIR FURNACE Application filed September 12, 1927.Serial No. 218,916.

The invention relatesto furnaces particu larly, although notexclusively, adapted for heating air for dwellings and the like.

The objects of the invention are to provide simple, durable andeconomical means adapted to admit; supplemental air to the burning gasesproduced in said furnace, thereby improving the combustion efficiency ofthe furnace, whereby the production of smoke-is eliminated or reduced;and to provide means whereby any of the various grades of". fuel andbituminouscoal may be efiiciently burned in said furnace. V

Other objects of the invention will be apparent by reference to thehereinafter description.

The invention consists in the combination and arrangement of the variousparts and elements, and in the details of the construc- 7 tion, as setforth and claimed. In the drawings: I Fig. 1 is a vertical section of afurnace .having the invention attached thereto, showin}; parts brokenaway;

Fig. 2 is an elevatonal view of the fire pot with parts broken away;

Fig. 3 is a section taken on a line corresponding ;to 3--3 in Fig. 1;and Fig. 4: is aside elevation of the collar.

In: the preferred construction of the in vention I provide the furnace 1comprising.

theusualcasing 2 suitably secured. to the front 2 which issuitably'fixed to the usual steel drum 3 contained within the casing.Inside the drum 3 is the inner lining 4 comprising the adjoiningfirebricks 5 having their outer sides '5 in contact-with the drum,whereby the usual fire pot 6 is formed.

*The usual door 7 is hingedly connected with through the front 2,permits air to pass.

the front 2' of the drum to-close the aligned opening 8 through the.drum 3 and the front 2, through which fuel, as coal, is insertedby-manual or mechanical means into the combustion chamber. The usualgrate 9 is suitably attached to the drum 3 for the usual purpose ofretaining the fuel within the fire pot 6. The main air inlet .3,

2 through the grate into the fire pot when the door 2", suitably hingedto the lower end 11 of the front, is open. It is apparent that thevarious parts previously described may be constructed in any manner,orof any material, suitable for theintended purposes and uses. p I

Formed in the outer side of the innerlining 4, adjacent its lower edge12, are the spaced apart circumferential grooves 13 and 14:.Intersecting the grooves13 and. 14: are the spaced apart verticalgrooves 15,; formed in the outer surface of the inner lining, wherebythe heated air warmed by the fire in the combustion chamber. is adaptedto circulate in the grooves 13,v 14

and .15. The openings 16 and 16, respec- 1,

the front whereby, when desirable,- the openings 16 and 16 may beclosed.

Bolted to the outer side 17 of the drum 3 is the pipe 18 having itsopening 19 reg istering with the hole 20 in the drum 3.

The hole 20 communicates with the groove 7 13 in the inner lining. v

The right'angle elbow 21 in the pipe 18 permits the upper end 22 of, thepipe to extend parallel with the adjacent side 23 of the drum 3. Theextreme upper end of the pipe 18 is received in the recess 24 ofthecollar 25 which is secured to the outer side of the drum 3, as by thebolts 26. The aperture 27 in thecollar communicates with the smoke orfire-gas hole or outlet" 28 in the drum. I Communicating with the recess24 isv the chamber 29 formed circumferentially ofthe collar.Communicating with the chamber 29 and the aperture 27, inthe collar,area plurality of spaced apart perforations 80,: whereby air receivedthrough the opening 16, in the drum 3, is adapted to pass through thegrooves 13, 141 and 15, pipe 18, recess 24, chamber 29 and holes 30 intothe aperture 27 of the collar whereby heated air is mixed with the smokeand-gases I that escape from the drum 3 into a suitable smoke pipe 31suitably connected with the collar 25 and the usual chimney flue 31.

The smoke pipe or tubular smoke and burned gas conductor 31, which isadapted to radiate heat, is positioned between the casing 2 and the drum8 from where heated air is suitably conducted to the rooms requiringheat. The smoke pipe is econon'iically maintained at a relatively hightemperature because the admission of heated air into the smoke and gasespassing from the drum 3 to the smoke pipe 31 results in elficientcombustion. Under certain circumstances it may be desirable merely toconnect a smoke pipe to the outer side of the-coll r and the chimneyfiue.

It is, therefore, apparent that I have invented a highly desirabledevice for the purposes intended and which will permit economical use ofvarious grades of coal 0 other fuel in hot air furnaces.

While I have chosen to illustrate the form and construction of theinvention by the herein drawings and explanations of the same, it isunderstood that the invention resides in the combination, arrangement ofthe parts and in the details of the construction, as hereinafterclaimed. t is further understood that changes in the precise embodimentof the invention, as disclosed herein, can be made within the scope ofwhat is claimed without departing from the spirit of the invention, asother expedients may readily suggest themselves to the art.

What I claim as new and desire to secure by Letters Patent is:

1. In a furnace, the combination with a casing, a fire drum in saidcasing and havmg a fire pot therein, an air inlet in said drum, a smokeoutlet in said drum, tubular means for conducting the smoke to the fine,and means connecting said tubular means with said drum at said outletwhereby products of combustion are adapted to flow from said chambertoward saidfiue, of an inner lining in said drum having acircumferential groove and a vertical groove in its outer side, andmeans to permit air to flow from said grooves into said second mentionedmeans. 2. In a furnace, the combination with a casing, a fire drum insaid casing and having a fire pot, an air inletin said drum, a productsof combustion outlet in said drum, and means for conducting the productsof combustion toward the flue, of an inner lining in said drum having aplurality of grooves therein, and means to convey air rom said groovesinto said means.

3. In a furnace, the combination with a casing, a fire drum in saidcasing, a fuel doorway through said casing and said drum, an air inletin said drum, a products of combustion outlet in said drum, and meansfor conducting said products of combustion and communicating with saidoutlet, of an inner lining in said drum, and means to convey' air fromadjacent the outer side of said drum into said means.

4. In a furnace, the combination with a fire drum having a fire pot andhaving a smoke and burned gas outlet, an inner lining in said drum,tubular means connected with said outlet, a perforated collar foradmitting air in the region of the junction of said parts, and meansextending through a side of said drum to convey said air from adjacentsaid inner lining into said collar.

5. In a furnace, the combination with a fire pot having an outlet, smokereceiving means connected with said outlet, means for admitting air inthe region of the junction of said parts, and means to convey heated airfrom adjacent the fire pot to said means whereby heated air is mixedwith the burned gas and smoke which escapes from said fire pot throughsaid outlet.

6. In a furnace, the combination with a drum having a fire pot andhaving anoutlet, an inner lining in said drum, smoke receiving meansconnected with said outlet, means for admitting air in the region ofthejunction of said parts, and a pipe to convey saidair from adjacentsaid inner linin to said means.

7. In a furnace, the combination witha drum having a fire pot and havinga smoke outlet,an inner lining in said chamber and having acircumferential groove inits outer side, smoke-conducting meansconnected with said outlet, a perforated collar for admitting air in theregion of the junction of said parts, and means to 'convey'said air fromsaid groove to said collar;

8. In a furnace, the combination with a drum having a fire pot andhaving a smoke outlet, smoke receiving means connected with said outlet,means for admitting air in s the region of the junction of said parts,and

means to convey saidair from a heated portion of said drum to sa1dmeans.

9. In a furnace, the combmation with a fire pot" having a smoke outlet,of an inner lining 1n said pot, tubular means connected with the chimneyflue and said outlet, a collar formed with a circumferential chamber andhaving a plurality of perforations leading from said chamber into theaperture in said collar and having a recess leading from nets ofcombustion, substantially as and for,

the purposes specified.

10. The combination with a furnace having a fire pot having an upwardsmoke outlet, of an inner lining" in said pot and having a groovetherein, tubular means communicating with the chimney'flue and saidoutlet, a collar formed with a circumferential chamber and having'aplurality of spaced apart perforations therein leading from the chamberinto the aperture in said collar, said collar having a recess leadingfrom its outer surface into said chamber and said collar formingcommunications between said outlet and said tubular means whereby theproducts of combustion in said furnace are adapted to pass from saidfire chamber through said aperture and into said tubular means, andmeans to convey air from said groove into said recess whereby heated airis mixed with said products of combustion, substantially as and for thepurposes specified. I

11. In a furnace, the combination with a fire pot having a fire-gasoutlet, and tubular means connected with the chimney flue and saidoutlet, of a collar formed with a circumferential chamber and having aperforation leading from said chamber into the aperture in said collarand having a recess leading from the outer surface into said chamber,and said collar connected to said furnace between said outlet and saidtubular means whereby air is adapted to be admitted into the products ofcombustion which passes from said fire pot through said aperture intosaid tubular means.

12. In a furnace, the combination with a casing, a fire drum in saidcasing, a fuel doorway extending'through said drum, an

a air inlet in said drum, a products of combustion outlet in said drum,and tubular means for conducting said products of combustion andcommunicating with said outlet, of an inner lining in said drum andhaving a groove therein, and means to convey air from said groove intosaid tubular means. I

13. In a furnace, the combination with a fire pot having an outlet, andmeans connected with the chimney flue and said outlet, of a collarformed with a circumferential chamber and having a perforation leadingfrom said chamber into the aperture in said collar and having a recessleading from the outer surface into said chamber, said collar connectedto said furnace between said outlet and said first mentioned meanswhereby products of combustion areadapted to pass from said fire potthrough. said aperture into said first mentionedmeans, and means toconvey air from adjacent said fire pot into said recess whereby heatedair is mixed with said products of combustion, substantially as and forthe purposes specified.

14. In afurnace, the combination with a fire pot having an upper outlet,of an inner lining in said pot and having a vertical groove and acircumferential groove in its outer side adjacent the lower portion ofsaid fire pot, means connected with the flue and said outlet, a collarformed with a circumferential chamber and having a plurality ofperforations leading from the chamber are adapted to pass from said firepot through said aperture and int-o said first mentioned means, andmeans to convey air from said grooves into said recess whereby heatedair is mixed with said smoke and gas previous to its entering the firstmentioned means, substantially as and for the purposes specified.

15. In a furnace, the combination with a casing, a fire drum in saidcasing and having a fire pot, an air inlet in said drum leading intosaid pot, an outlet in said drum leading from said chamber, airadmission means communicating with said outlet, of an inner lining insaid drum having a groove therein, and means to convey air from saidgroove into said air admission means.

16. The combination with a furnace having a fire pot havingan uppersmoke outlet, means communicating with the chimney flue and said outlet,a collar formed with a circumferential chamber and I having a pluralityof spaced apart perforations therein leading from the chamber into theaperture in said collar, said collar having a recess leading from itsouter surface into said chamber whereby air-is received in the aperturefrom said recess, and said collar forming communications between saidout let and said first mentioned means whereby the products ofcombustion are adapted to be mixed with airjas .it passes from said firepot through said aperture and into said first mentioned means.

17 The combination with a furnace having a fire pot having an upperfire-gas outlet, a collar formed, with a circumferential chamber andhaving a plurality of spaced apart perfortions therein leading from thechamber into the aperture in said collar,

said collar having a recess leading from its outer surface into saidchamber whereby air is received in the aperture from said recess, andsaid collar forming communications between said outlet and the fluewhereby the products of combustion are adapted to be mixed with air asit passes from the said fire pot through said aperture.

JAMES ELIPHAS WITTE.

